title: [Cost-effectiveness in the detection of influenza H1N1: clinical data versus rapid tests].
abstract: OBJECTIVE
  Evaluate the performance of clinical data and the rapid influenza diagnostic test (RIDT) in diagnosing influenza H1N1, and analyze the cost-benefit of using this diagnostic tool.
  
  
  METHODS
  The RIDT was used for patients who came to four hospitals in Mexico City with an influenza-like illness (ILI) in October and November 2009. The diagnostic performance of the ILI clinical data and the RIDT was compared to that of the real-time reverse transcription polymerase chain reaction (rRT-PCR) test. The rRT-PCR test was conducted in a reference laboratory and blinded to the results of the RIDT. An economic evaluation also was conducted to estimate the budgetary impact of using the RIDT.
  
  
  RESULTS
  The study included 78 patients, 39 of whom tested positive for influenza H1N1 and 6 tested positive for seasonal influenza A, according to the results of the rRT-PCR. The ILI clinical data yielded a sensitivity of 96% and specificity of 21%; the RIDT yielded a sensitivity of 76% and specificity of 82%; and the ILI clinical data and RIDT together yielded a sensitivity of 96% and specificity of 100%. The positive likelihood quotient for ILI-headaches was 31.5 and that of ILI-odynophagia, 330. The use of RIDT yielded savings of US$12.6 per each suspected case.
  
  
  CONCLUSIONS
  Use of the RIDT to aid in the diagnosis of influenza H1N1 increases certainty and lowers the average cost per suspected and infected patient.
authors.affiliation: Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, D.F., México.
authors.forename: Jorge
authors.initials: J
authors.lastname: González-Canudas
authors.forename: Jimena María
authors.initials: JM
authors.lastname: Iglesias-Chiesa
authors.forename: Yulia
authors.initials: Y
authors.lastname: Romero-Antonio
authors.forename: Carolina
authors.initials: C
authors.lastname: Chávez-Cortes
authors.forename: Juan Gabriel
authors.initials: JG
authors.lastname: Gay-Molina
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Rivas-Ruiz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000191:economics; D000956:Antigens, Viral / Q000032:analysis; D000998:Antiviral Agents / Q000191:economics / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003199:Computer Systems / Q000191:economics; D003362:Cost-Benefit Analysis; D003951:Diagnostic Errors; D042241:Early Diagnosis; D005260:Female; D006760:Hospitalization / Q000191:economics; D006786:Hospitals, Urban; D006801:Humans; D007118:Immunoassay / Q000191:economics* / Q000379:methods; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000188:drug therapy / Q000821:virology; D008297:Male; D008800:Mexico; D008875:Middle Aged; D010808:Physical Examination / Q000191:economics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000191:economics; D016037:Single-Blind Method; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
chemical_list: D000956:Antigens, Viral; D000998:Antiviral Agents